docs: def _compute_mean(self, C, rup, dists, sites, imt):
          """
          Returns the mean ground motion acceleration and velocity
          """
          mean = (self._get_magnitude_scaling_term(C, rup.mag) +
                  self._get_distance_scaling_term(C, rup.mag, dists.rrup) +
                  self._get_site_amplification_term(C, sites.vs30))
          # convert from cm/s**2 to g for SA and from m/s**2 to g for PGA (PGV
          # is already in cm/s) and also convert from base 10 to base e.
          if imt.name == "PGA":
              mean = np.log((10 ** mean) * ((2 * np.pi / 0.01) ** 2) *
                            1e-2 / g)
          elif imt.name == "SA":
              mean = np.log((10 ** mean) * ((2 * np.pi / imt.period) ** 2) *
                            1e-2 / g)
          else:
              mean = np.log(10 ** mean)
  
          return mean